An acronym for 'Know It All'. One of those people who has an answer for everthing no matter what the subject matter is. Especially those who answer a question with a holier-than-thou attitude.

Bob - "What is pi? I forgot"

Andy the Kia - "The mathematical constant pi is an irrational real number, approximately equal to 3.14159265358979323846.., which is the ratio of a circle's circumference to its diameter in Euclidean geometry, and has many uses in mathematics, physics, and engineering."